Various surgical procedures are routinely carried out intravascularly or intraluminally. For example, in the treatment of vascular disease, such as arteriosclerosis, it is a common practice to invade the artery and insert an instrument (e.g., a balloon or other type of catheter) to carry out a procedure within the artery. Such procedures usually involve the percutaneous puncture of the artery so that an insertion sheath can be placed in the artery and thereafter instruments (e.g., catheter) can pass through the sheath and to an operative position within the artery. Intravascular and intraluminal procedures unavoidably present the problem of stopping the bleeding at the percutaneous puncture after the procedure has been completed and after the instruments (and any insertion sheaths used therewith) have been removed. Bleeding from puncture sites, particularly in the case of femoral arterial punctures, is typically stopped by utilizing vascular closure devices, such as those described in U.S. Pat. Nos. 6,179,963; 6,090,130; and 6,045,569 and related patents that are hereby incorporated by reference.
Typical closure devices such as the ones described in the above-mentioned patents sandwich the puncture site with an internal anchor and an external sealing plug. The internal anchor and external sealing plug are attached by a suture. The suture is typically slip-knotted proximal of the sealing plug to cinch and hold the sealing plug adjacent to the anchor. A tamping tube is often used to force the sealing plug toward the anchor. Even after tamping the sealing plug and cinching the suture, the suture extends from the puncture and through the skin. It is desirable, however, to cut the suture percutaneously to promote healing.
Consequently, an operator usually pulls the suture, stretching the suture a certain length outside of the incision. The suture is then cut as close as possible to the base of the incision, which releases the pulling pressure and usually springs the suture back within the incision below the outside skin level. Thus, the suture is typically not exposed from the incision after it is cut. However, there is a risk of pulling too hard on the suture and compromising the seal of the anchor and the sealing plug. In addition, the small amount of stretch available by pulling the suture usually leaves the end of the suture very close to, or even protruding slightly from, the surface of the skin. Therefore, there is a need for cutting sutures percutaneously without excessive pulling on the suture, such that the sutures are cut well below the skin surface.